I always find it interesting to compare ringing totals with the previous years as with similar effort from year to year they give an indication of productivity. To early to do this for most species but with all the data in it is possible to look at warbler trends in this year which saw poor weather early in the breeding season but better weather later.
Blackcap at 116 is just slightly up on both 2012 (102) and the five year average of 97. Chiffchaff at 180 has a similar trend, up on 2012(159). The species which has seen the greatest decline though is Willow Warbler with 349 ringed this year compared with 510 in 2012 and a five year average of 476. This fits in well with the general feeling that the breeding population was down this year. On the surveyed part of Warton Crag the breeding population was down from 29 pairs in 2012 to 21 this year. By contrast Whitethroat were up from just 70 in 2012 to 173 this year as were Lesser Whitethroat from 30 last year to 48 this year.
Two other species which several members of the group have commented on as being scarce this autumn are Long-tailed Tit and Goldcrest. So far this autumn we have caught only 37 Long tails compared with 108 in 2012 and 27 Goldcrest compared with 184 in 2012 but there is still time for these to appear.
John
1 comment:
The autumn passage of Willow Warbler has been inexplicably dreadful this year e.g. also at Walney suggesting that the Scottish breeding birds did really badly but why? Or did they just "jump overhead" during the rather good migration weather for large chunks of the early autumn?. Would be interesting to see breeding season assessments from Scotland. Blackcaps really poor at Heysham - both breeding birds and passage
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